CLEVELAND — A common B vitamin might actually be harmful for your health. Cleveland Clinic researchers have made a significant breakthrough in understanding how high levels of niacin could lead to cardiovascular diseases. The study identifies a new pathway through which excessive dietary niacin contributes to heart disease, challenging previous beliefs about the vitamin’s health benefits.
Niacin, also known as vitamin B-3, is prevalent in the Western diet and has been widely fortified in foods such as flour, cereals, and oats for decades to prevent nutritional deficiencies. However, this new research indicates that overconsumption of niacin can lead to elevated levels of a metabolite known as 4PY, which is now linked to an increased risk of heart attack, stroke, and other cardiovascular events.
The study’s findings are based on a combination of large-scale clinical studies and preclinical experiments. Researchers discovered that high circulating levels of 4PY are strongly associated with the development of cardiovascular diseases, primarily through its role in triggering vascular inflammation. This inflammation can damage blood vessels, leading to atherosclerosis, a condition characterized by stiff, hardened arteries.
“What’s exciting about these results is that this pathway appears to be a previously unrecognized yet significant contributor to the development of cardiovascular disease,” says study lead author Dr. Stanley Hazen, Chair of Cardiovascular and Metabolic Sciences at Cleveland Clinic’s Lerner Research Institute and Co-Section Head of Preventive Cardiology in the Heart, Vascular & Thoracic Institute, in a media release. “What’s more, we can measure it, meaning there is potential for diagnostic testing. These insights set the stage for developing new approaches to counteract the effects of this pathway.”
Researchers also delved into genetic links between 4PY and vascular inflammation, offering a foundation for future studies aimed at reducing or preventing this inflammation. The work opens the door to developing new approaches to counteract the effects of the 4PY pathway, potentially revolutionizing how we view niacin’s role in our diet and its implications for heart health.
Despite niacin’s long-standing recommendation for lowering cholesterol, the study suggests a reevaluation of niacin fortification in food and the use of niacin supplements.
“The main takeaway is not that we should cut out our entire intake of niacin — that’s not a realistic approach,” notes Dr. Hazen. “Given these findings, a discussion over whether a continued mandate of flour and cereal fortification with niacin in the U.S. could be warranted.”
The study’s broader implications include a potential rethinking of dietary guidelines and fortification practices, especially in the United States, where niacin fortification has been mandated for over fifty years.
“Niacin’s effects have always been somewhat of a paradox,” explains Dr. Hazen. “Despite niacin lowering of cholesterol, the clinical benefits have always been less than anticipated based on the degree of LDL reduction. This led to the idea that excess niacin caused unclear adverse effects that partially counteracted the benefits of LDL lowering. We believe our findings help explain this paradox. This illustrates why investigating residual cardiovascular risk is so critical; we learn so much more than what we set out to find.”
As cardiovascular diseases remain a leading cause of death worldwide, the findings from this study underscore the need for a nuanced understanding of how vitamins and other nutrients affect heart health. Further long-term studies are required to fully assess the impact of chronic 4PY elevation on heart disease, but Dr. Hazen’s ongoing research into factors contributing to cardiovascular risk continues to provide valuable insights into the prevention and treatment of these conditions.
The study is published in the journal Nature Medicine.